JPH08332143A - Cooker - Google Patents

Abstract

PURPOSE: To prevent the state of generating abnormal heating and to improve safety by stopping generating heat from a heat generating means when a detected temperature at the time of generating the prescribed value of heat from the heat generating means is within a prescribed temperature range and the increase of the detected temperature is less than a prescribed temperature rising value. CONSTITUTION: A rice cooker is provided with induction coils 11 and 12 as heating means, which are positioned at the lower part and lower side surface part on the outer surface of a bottomed cylindrical inner frame 2 while being separated from a heat generating layer 5 of a pan 4 just for a prescribed distance, for the induction heating of the heat generating layer 5. Besides, this rice cooker is provided with a body heater 21 composed of a cord heater, etc., as a heating means for insulating the temperature of the inner frame 2 at the upper outer side surface part of the inner frame 2. At the time of starting cooking rice, a detected temperature PO of a pan temperature sensor 22 is stored, the heat generation of the pan 4 is started and after the lapse of prescribed time T from the start of rice cooking, a pan temperature P1 is read again. When temperature difference P1-P0 is less than a prescribed temperature rising value α, the heat generation of the pan 4 is stopped by judging that any abnormality exists in the pan temperature sensor 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooker such as a rice cooker in which the container itself generates heat, and more particularly to a cooker with improved safety when the temperature detecting means fails.

[0002]

2. Description of the Related Art Conventionally, a cooker such as a rice cooker which heats a container itself by electromagnetic induction heating, detects the temperature of the container by a temperature sensor, and controls heat generation amount, heat generation, and heat generation stoppage for cooking. It has been known. However, in the conventional cooker of this type, the following problems occur when the temperature detection accuracy of the container deteriorates.

The deterioration of the temperature detection accuracy of the container is caused by foreign matter such as rice grains being caught between the container and the temperature sensor during use.
The temperature sensor is not in contact with the container due to manufacturing errors, the contact between the container and temperature sensor deteriorates due to dimensional changes over time due to use, and this This occurs when the thermal contact between the heat sensitive plate and the sensor body is deteriorated, the temperature resistance characteristic of the thermistor element that is the sensor body is different, or this characteristic changes with time, or other Can happen for some reason. If the temperature detection accuracy of the container deteriorates in this way, even if the temperature of the container is high due to heat generation, the temperature sensor detects a temperature lower than the actual temperature of the container, and abnormal heat generation occurs even if the temperature is abnormally high. In some cases, the temperature of the container cannot be detected and the container continues to generate heat, which causes abnormal heating of the main body, which activates the thermal fuse for safety, and then the product cannot be reused. In addition, the resin body may be melted before the thermal fuse operates.

In addition, during cooking, by controlling the cooking time,
For example, if boiling is not detected even after cooking for a predetermined period of time, and the cooking is stopped by detecting an abnormality, if the temperature detection accuracy of the container deteriorates as described above, the cooked product will be in a state of raw cooking. However, there is a problem that the cooked food becomes inedible.

[0005]

As described above, in the conventional cooker, if the accuracy of detecting the container temperature by the temperature detecting means is deteriorated for some reason, abnormal heating may occur, and an abnormal error may occur. There was a problem that cooking stopped unnecessarily due to detection.

The present invention is intended to solve such a problem, and can detect an abnormality in the detection of the container temperature by the temperature detecting means, and when the accuracy of detecting the container temperature deteriorates, the abnormal heating is performed. A first object of the present invention is to provide a cooker capable of preventing the above. Furthermore, in this cooker,
A second object is to stop the heat generation before the operation of the thermal fuse when the detection accuracy of the container temperature deteriorates. A third object is to make it possible to accurately detect an abnormal detection of the container temperature even if there is an error in the power supply voltage. A fourth object is to prevent cooking from being stopped unnecessarily due to erroneous detection of abnormality.

[0007]

In order to achieve the first object, the cooker according to the invention of claim 1 has a container for containing the food, a heating means for heating the container, and a container for heating the container. The temperature detecting means for detecting the temperature, the cooking control means for controlling the heat generation amount of the heat generating means so that the detected temperature of the temperature detecting means becomes a cooking temperature set within a predetermined temperature range, and the heat generating means. Heat generation stopping means for stopping the heat generation of the heat generating means when the temperature detected by the temperature detecting means when the predetermined amount of heat is generated is within the predetermined temperature range and the increase in the detected temperature is less than the predetermined temperature increase value. Be prepared.

According to a second aspect of the invention, in the cooking device of the first aspect, in order to achieve the second object, a temperature fuse connected to the heat generating means in a series circuit is provided, and the predetermined amount of heat is: It is set within the range in which the thermal fuse does not operate when the container is empty.

According to a third aspect of the invention, in the cooker according to the first aspect of the invention, in order to achieve the third object, the predetermined temperature rise value is a power supply voltage supplied to the heating means of 80.
The temperature is set to be not lower than V and not higher than the temperature rise that occurs during normal operation.

According to a fourth aspect of the invention, in the cooker according to the first aspect of the invention, in order to achieve the fourth object, the predetermined temperature rise value is a value when the temperature detecting means is completely separated from the container. It is set to be equal to or higher than the detected temperature rise that occurs in 1).

In order to achieve the first object, the cooker according to the fifth aspect of the present invention has a container for containing food, a heat generating means for generating heat from the container, and a temperature detecting device for detecting the temperature of the container. Means, cooking control means for controlling the amount of heat generated by the heat generating means so that the temperature detected by the temperature detecting means becomes a cooking temperature set within a predetermined temperature range, and heat is generated by the cooking control means after starting cooking. Cooking stop means for causing the means to generate a predetermined amount of heat and then stopping the heat for a predetermined time, and when the increase in the temperature detected by the temperature detecting means after the end of the heat generation is less than a predetermined temperature increase value, stop cooking. It is equipped with and.

[0012]

In the cooker according to the first aspect of the invention, the container containing the food to be cooked is heated by the heat generating means for cooking. At that time, the temperature detecting means detects the temperature of the container, and the cooking control means controls the heat generation amount of the heat generating means so that the detected temperature becomes the set cooking temperature within the predetermined temperature range. When the temperature detected by the temperature detecting means when the heat generating means generates a predetermined amount of heat is within the predetermined temperature range and the increase in the detected temperature is less than the predetermined temperature increase value, there is an abnormality in the detection of the container temperature by the temperature detecting means. As a thing, the heat generation stopping means stops the heat generation of the heat generation means.

In the cooking device of the second aspect of the invention, the thermal fuse does not operate even if the heat generating means generates the predetermined amount of heat while the container is empty. Therefore, an abnormality in the detection of the container temperature by the temperature detecting means is detected before the operation of the temperature fuse.

In the cooking device of the third aspect of the invention, even if there is an error in the power supply voltage, if the power supply voltage is 80 V or higher, that is, if the power supply voltage is close to the normal one, the power supply voltage is low, and the heating means Even if the calorific value of the container is low, the predetermined temperature rise value for detecting abnormalities in the container temperature detection is 80 V
Since the temperature is set to be equal to or lower than the temperature rise at the time, it is not mistakenly determined that there is an abnormality in the container temperature detection.

In the cooking device according to the fourth aspect of the present invention, for example, when a foreign substance having a certain degree of heat conductivity such as rice grains is interposed between the temperature detecting means and the container, the abnormal temperature of the container temperature is detected. Since the predetermined temperature rise value for setting is set to be equal to or higher than the detected temperature rise that occurs when the temperature detecting means is completely separated from the container, it is not mistakenly determined that the container temperature is abnormally detected. .

In the cooking device of the fifth aspect of the invention, the container containing the food to be cooked is heated by the heat generating means for cooking.
At that time, the temperature detecting means detects the temperature of the container, and the cooking control means controls the heat generation amount of the heat generating means so that the detected temperature becomes the set cooking temperature within the predetermined temperature range. After starting the cooking by the cooking control means, the heat generating means is caused to generate a predetermined amount of heat, and then the heat generation is stopped for a predetermined time, but when the rise in the temperature detected by the temperature detecting means after the end of the heat generation is less than the predetermined temperature rise value. The cooking stop means stops cooking, assuming that the detection of the container temperature by the temperature detection means is abnormal. By thus detecting the abnormality from the temperature detected by the temperature detecting means after the end of the heat generation stop time, it is possible to eliminate the heat influence on the temperature detecting means due to the heat generation of the container, and it is possible to perform accurate detection.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the cooker according to the present invention will be described below with reference to the drawings. Although the cooker of this embodiment is a rice cooker, in FIG. 4 which is an overall sectional view thereof,
Reference numeral 1 denotes a cooker main body, which comprises a bottomed cylindrical inner frame 2 having an open top surface, and an outer frame 3 having the inner frame 2 inside and forming an outer shell of the cooker main body 1. There is. The inner frame 2 and the outer frame 3 are made of plastic. Reference numeral 4 denotes a pot that is a container that accommodates rice, water, and the like to be cooked inside, and the pot 4 is formed of an aluminum material as a cylinder with a bottom and an open top. It is to be detachably accommodated in. A heating layer 5 made of a magnetic metal material for heating the pot 4 is provided on the outer surface of the pot 4 at the bottom and lower portions of the side surfaces.

In addition, the outer surface of the inner frame 2 is positioned at a bottom portion and a lower portion of a side surface thereof at a predetermined distance from the heat generating layer 5 of the pan 4, and is an induction means for heating the heat generating layer 5 by induction heating. Coils 11 and 12 are provided. These induction coils 11 and 12 are covered with a plastic coil cover 13 from the outside and fixed to the inner frame 2. The induction coil 1 located above the coil cover 13 is located outside the coil cover 13.
Multiple ferrite cores 14 orthogonal to the winding direction of 1 and 12
Is provided. The ferrite core 14 is made by sintering a material having iron oxide as a main raw material and high magnetic permeability. Further, a magnetic shield 15 made of an aluminum material for preventing leakage of magnetic flux is provided facing the outer surfaces of the induction coils 11, 12.

On the upper part of the outer surface of the inner frame 2, a body heater 21 such as a cord heater is provided as a heating means for keeping the inner frame 2 warm. Also, the inner frame 2
A thermal fuse 22 is provided in the lower part of the. Further, on the upper side of the central portion of the coil cover 13, a pot temperature sensor is provided as a temperature detecting means for detecting the outer surface temperature of the pot 4.
23 is provided to be movable up and down. This pan temperature sensor 23
Is a thermosensitive plate of the outer shell in which a negative characteristic thermistor is incorporated. The pot temperature sensor 23 is urged upward by a spring 24 which is an elastic member, and penetrates the bottom portion of the inner frame 2 and projects upward.
It contacts the bottom of the pan 4. Also, the pot temperature sensor
A switch lever 25 fixed to 23 penetrates the coil cover 13 and projects downward.

A control board 26 is provided in the lower portion of the cooker body 1. The control board 26 is provided with an inverter circuit for supplying a predetermined high frequency current to the induction coils 11 and 12. The control board 26 is also provided with a pan switch 28 having an opening / closing member 27 operated by the switch lever 25 and detecting the presence or absence of the pan 4. That is,
If the pan 4 is not housed in the inner frame 2, the switch lever 25 pushed up by the spring 24 and moved up together with the pan sensor 23 lifts the opening / closing element 27, while the pan 4 is housed in the inner frame 2. , The pan 4 pushes down the pan temperature sensor 23 and the switch lever 25, and in conjunction with this, the door 27
Also goes down. As a result, the presence or absence of the pan 4 is detected.

On the other hand, the inner frame 2 is provided at the rear of the cooker main body 1.
A space 31 is formed between the outer frame 3 and the outer frame 3, and a heating substrate 32 is arranged in the space 31. A switching element 33 is mounted on the heating substrate 32. This switching element
The numeral 33 constitutes a power interruption driving means for driving the interruption of the high frequency current of the induction coils 11 and 12, and since it is a heat generating component, the radiator 34 is attached. Further, an exhaust port 35 is provided above the heating substrate 32 in the upper rear portion of the outer frame 3, and is located below the heating substrate 32 in the lower rear portion and bottom portion of the outer frame 3. An intake port 36 is provided. Further, a cord reel 38 for winding the power cord 37 is provided on the front side of the bottom of the outer frame 3. Although not shown, at the tip of the power cord 37, 1
A power plug that is detachably connected to an outlet of a commercial AC power supply of 00V is provided.

Reference numeral 41 is a lid that covers the upper opening of the pot 4 so as to be openable and closable. The lid 41 is attached while forming an outer lid 42 made of plastic or the like, an outer lid cover 43 provided along the lower outer periphery of the outer lid 42, and forming a space under the outer lid 42. A heat radiating plate 44 made of an aluminum member is provided, and an inner lid 45 that closes the upper opening of the pan 4 is detachably engaged with the lower portion of the heat radiating plate 44 via an inner lid retainer 46. Reference numeral 47 denotes an annular lid packing sandwiched and held between the outer lid cover 43 and the heat radiating plate 44, and when the lid body 41 is closed, the lower end of the lid packing 47 is a flange portion on the upper surface of the pan 4. Stick to. A clamp button 48 is provided on the front side of the lid body 41, and by pushing and operating the clamp button 48, the lid body 41 can be opened around a hinge 49 provided on the rear side of the lid body 41 as a rotation center. . Meanwhile, the lid
On the upper surface of the heat dissipation plate 44 forming the lower surface of 41, a lid heater 51 such as a cord heater is provided as a heating means for heating the heat dissipation plate 44 during rice cooking and heat retention. Further, a lid temperature sensor 52 including a negative characteristic thermistor is provided on the upper surface of the heat radiating plate 44 as a lid temperature detecting means for detecting the temperature of the heat radiating plate 44. The lid heater 51 constitutes a parallel circuit with the body heater 21 of the inner frame 2. In addition, 53
Is a steam port for discharging the steam from the pan 4 to the outside, 54 and 55 are
The operation panels are provided on the upper portion of the outer lid 42 and the front surface of the outer frame 3, respectively.

Next, the circuit configuration of the rice cooker will be described with reference to FIG. In the figure, reference numeral 61 denotes a microcomputer as a control means, which is, as is well known, a control device 62 and a computing device 63 which constitute a microprocessor, a timer device 64 including various counters, a ROM and a RAM. A storage device 65 including the above is provided. An input device 66 is connected to the input side of the microcomputer 61, and the pan temperature sensor 23,
The lid temperature sensor 52 and the pan switch 28 are connected to an operation switch 67 and a power failure detection circuit 68 which are operation means provided on the operation panel 54. On the other hand, an output device 71 is connected to the output side of the microcomputer 61, and through this output device 71, induction heating means (heat generating means) 72 for electromagnetic induction heating the pan 4, the body heater 21 and the lid are provided. A heater driving unit 73 having a switch unit such as a triac for controlling the heater 51 to connect and disconnect at the same time is connected. Output device
In addition to these, the display drive means 76, 77 for controlling the display of the LED display means 74 for displaying the operation states such as rice cooking and heat retention and the LCD display means 75 for displaying the time and the like are connected to 71. At the same time, the buzzer drive means 79 for controlling the ringing of the buzzer 78 for notifying the end of cooking rice is connected.

The microcomputer 61 inputs the operation signal of the operation switch 67 for starting rice cooking, heat retention, etc., the temperature data from the pan temperature sensor 23 and the lid temperature sensor 52, and the pan detection signal from the pan switch 28. As information, in addition to this input information, by time information from the clock device 64,
The induction heating means 72, the lid heater 51 and the body heater 21, the LED display means 74, the LCD display means 75, and the buzzer 78 are controlled in accordance with the control sequence set in the ROM of the storage device 65 in advance. Reference numeral 81 is a power failure backup means connected to the output device 71, which supplies auxiliary power to the microcomputer 61 via the microcomputer drive circuit 82 at the time of power failure and retains the contents stored in the storage device 65. Is.

The induction heating means 72 has a high-frequency current generator 83 for supplying a predetermined high-frequency current based on the output signal from the microcomputer 61, and disconnects the induction coils 11 and 12 while varying the high-frequency current value. And an output adjusting circuit 84 for controlling the electric power are provided. When a high frequency current is supplied to the induction coils 11 and 12, the induction coils 1 and 12
An alternating magnetic field is generated in 1 and 12, an eddy current is generated in the heating layer 5 of the pan 4 in the magnetic field, and this eddy current is converted into Joule heat, so that the heating layer 5 generates heat and the pan is heated. 4 is configured to be heated. The thermal fuse 22 is connected in a series circuit in a circuit that supplies power to the high-frequency current generator 83 of the induction heating means 72 and a circuit that supplies power to the heaters 21 and 51. When the temperature becomes higher than a predetermined temperature, it operates and cuts off the power supply.

As described above, the microcomputer 61
The temperature sensor 23,
The cooking control means for controlling the heat generation amount by the induction heating means 72 and the heat generation amounts of the heaters 21, 51 and the pan 4 for a predetermined time T so that the detected temperature of 52 becomes a cooking temperature set within a predetermined temperature range. When the temperature detected by the temperature sensor 23 when a predetermined amount of heat is generated is within the predetermined temperature range and the increase in the detected temperature is less than the predetermined temperature increase value α, the heat generated by the induction heating means 72 and the heaters 21, 51 And a heat generation stopping means for stopping the heat generation of. In controlling the amount of heat generated by the cooking control means, the control temperature of the pan temperature sensor 23 during rice cooking and heat retention is managed within a temperature range of -10 ° C to 130 ° C. For example, before hot rice cooking to promote water absorption of rice is 45 ℃
The temperature is controlled to 70 ° C, the temperature at which rice heating is stopped and the temperature is shifted to 120 ° C, and the heat retention control is set to 65 ° C to 72 ° C. Also, the control temperature of the lid temperature sensor during rice cooking and heat retention is
Control within the temperature range of -10 ℃ to 120 ℃. For example, the temperature should be 110 ℃ during the warming and 69 ℃ -76 ℃ during the heat retention. The temperature control itself has the same configuration as the conventional rice cooker. Further, in the present embodiment, the predetermined time T is set to 120 seconds from the start of cooking, that is, rice cooking, and the predetermined temperature increase value α is set to 30 ° C. However, it is not limited to this. Absent.

However, the predetermined time T is set to such a time that abnormal heating such as melting of plastic parts such as the container body 1 cannot occur even if continuous heat generation of the pan 4 continues during that time. The predetermined temperature rise value α is determined by the pan temperature sensor 23.
When the temperature detection by the pan is normal, the temperature is set to be less than the rise value of the temperature detected by the pan temperature sensor 23 that occurs when the T pan 4 continues to generate heat for the predetermined time. Further, the predetermined time T
Is set within the time during which the thermal fuse 22 does not operate when the pot 4 is empty. Further, the predetermined temperature rise value α
Indicates that the pot 4 and the pot temperature sensor 23 are originally thermally coupled, that is, the contact between the heat-sensitive plate of the pot temperature sensor 23 and the pot 4 is good, and there is no abnormality in temperature detection accuracy. In this state, when the power supply voltage supplied to the induction heating means 72 is 80 V or higher, the temperature is set to be slightly lower than the temperature rise of the pan temperature sensor 23 caused by the heat generation for the predetermined time T. There may be an error of about ± 10V in a 100V commercial AC power supply, but in consideration of this error, the above-mentioned 80, which is sufficient as a lower limit when the power supply is normal.
The value V is set. Along with this, the predetermined temperature increase value α is set to be equal to or higher than the increase in the temperature detected by the pan temperature sensor 23 that occurs when the pan temperature sensor 23 is completely separated from the pan 4.

Next, with reference to the graph of FIG. 1 and the flowchart of FIG. 2, the operation of the above-mentioned configuration will be described. In the upper graph of FIG. 1, the vertical axis represents the temperature detected by the pan temperature sensor 23, and the horizontal axis represents time. The column graph on the lower side of FIG. 1 shows the timing of heat generation of the pan 4. The same applies to FIGS. 5 and 7 described later.

When rice cooking is started (step S1), the temperature P0 detected by the pan temperature sensor 23 at the start of rice cooking is stored (step S2), and heat generation of the pan 4 is started (step S3). This form of heat generation is continuous heat generation. Then, when a predetermined time T has elapsed from the start of rice cooking, the pot temperature sensor
The detected temperature P1 of 23 is read again (steps S4, S5), and as shown by the broken line graph in FIG.
If is greater than or equal to α, it is determined that the temperature detection by the temperature sensor 23 is normal, and the rice cooking heating is continued as it is (steps S6 and S7). On the other hand, as shown by the solid line graph in FIG. 1, if the rise in detected temperature P1-P0 is less than α,
Assuming that the temperature detection by the pan temperature sensor 23 is abnormal (step S8), the heat generation of the pan 4 is stopped (step S).
9).

According to the configuration of the above embodiment, when the temperature rise of the pan temperature sensor 23 when the T pan 4 is heated for a predetermined time from the start of rice cooking is less than the predetermined temperature rise value α, the temperature detection is abnormal. As described above, the heat generation of the pan 4 is stopped, and the predetermined time T is set so that abnormal heating such as melting of plastic parts such as the container body 1 does not occur. The temperature rise value α is set to less than the rise in the detected temperature that occurs when temperature detection is normal, so if for some reason the temperature detection accuracy of the pan temperature sensor 23 deteriorates, it can be detected accurately. The heat generation can be stopped before abnormal heating due to deterioration of temperature detection accuracy occurs. This allows the thermal fuse
It is possible to prevent the risk of melting of plastic parts such as the main body 1 without relying on only 22 for safety, and the safety is improved. On the other hand, if the temperature detection by the pan temperature sensor 23 is normal, rice cooking can be continued without erroneous detection.

Further, since the predetermined time T is set within the time when the temperature fuse 22 does not operate when the pot 4 is empty, it goes without saying that the cooked food is in the pot 4 during rice cooking. However, if the pot 4 is heated due to misuse or the like when the pot 4 is empty, that is, even if the temperature rises quickly due to no load, deterioration of the temperature detection accuracy is detected. When the thermal fuse 22 works before the pan 4
It is possible to stop the fever. As a result, it is possible to prevent a situation in which the thermal fuse 22 operates due to the abnormal heat generation of the pan 4 and the reuse becomes impossible after that.

By the way, if the predetermined temperature rise value α is set too high, in the unlikely event that the power supply voltage is as low as 90 V and the amount of heat generated by the pan 4 is small, the temperature of the pan temperature sensor 23 cannot be detected. Even if it is normal, there is a possibility that the temperature rise will be less than the predetermined temperature rise value α and the temperature detection will be erroneously detected to be abnormal, and the rice cooking heating will be stopped unnecessarily. However, in the above embodiment, the predetermined temperature rise value α is set to be slightly lower than the temperature rise caused by the heat generation for the predetermined time T when the power supply voltage supplied to the induction heating means 72 is 80 V or higher. Even if the power supply voltage is low to some extent and the amount of heat generated by the pan 4 is low, it is not erroneously detected that there is an abnormality in the temperature detection, and the abnormality can be accurately detected. In addition, as in this embodiment, 80V
If the prevention of erroneous detection is assured by, when the power supply voltage is 90V and the pot 4 is heated by the induction heating means 72 at about 1200W, even if the voltage drop is about 5V, the pot temperature sensor 23 is sufficiently abnormal. The false detection of can be prevented.

The predetermined temperature rise value α for detecting an abnormality in temperature detection is set to be equal to or higher than the rise in the temperature detected by the pan temperature sensor 23 that occurs when the pan temperature sensor 23 is completely separated from the pan 4. Therefore, for example, when a foreign substance having a certain degree of heat conductivity such as rice grains is interposed between the heat sensitive plate of the pan temperature sensor 23 and the pan 4, it is detected that the temperature detection is abnormal only by that. There is no such thing. That is, when rice grains are present between the heat sensitive plate of the pan temperature sensor 23 and the pan 4, the pan temperature sensor 23 can detect the temperature to some extent, but in such a case, It is possible to continue the rice cooking as it is, without the abnormal detection of the temperature detection being erroneously detected and the rice cooking being stopped unnecessarily. On the other hand, only when the normal temperature detection cannot be performed completely, the temperature detection abnormality can be surely detected, and the rice cooking can be stopped.

The graph of FIG. 5 and the flowchart of FIG. 6 show the second embodiment of the present invention. In the second embodiment, the microcomputer 61 has, as a function of its software, the pan 4 for the first predetermined time T from the start of rice cooking.
1. After heat generation for a predetermined amount of heat, stop heat generation for T2 for a second predetermined time, and when the temperature detected by the temperature sensor 23 after the end of the second predetermined time T2 is less than or equal to a predetermined temperature increase value α1 ,
A cooking stopping means for stopping cooking by stopping the heat generation by the induction heating means 72 and the heaters 21, 51 is constituted.
Then, in the present embodiment, the first predetermined time T1 is
It is set to 300 seconds from the start of rice cooking, and the second predetermined time T2 is set to the subsequent 300 seconds. The predetermined temperature rise value α1 is set to 30 ° C. Of course, it is also possible to set other than these values. However, the heat generation amount of the pot 4 during the first predetermined time T1 or during that time is set to a time at which abnormal heat such as melting of plastic parts due to the heat generation cannot occur. The predetermined temperature rise value α1 is set to be less than the rise value of the temperature detected by the pan temperature sensor 23 that occurs when the temperature detection by the pan temperature sensor 23 is normal. Furthermore, the relationship between the first predetermined time T1 and the operation of the thermal fuse 22, the relationship between the predetermined temperature increase value α1 and the power supply voltage, and the predetermined temperature increase value α1 and the pan temperature sensor 23 and the pan 4 The relationship with the distance is set in the same manner as in the first embodiment.

Then, when the rice cooking is started (step S11
), The temperature P0 detected by the pan temperature sensor 23 at the start of rice cooking is stored (step S12), and the heat generation of the pan 4 starts (step S13). This form of heat generation is an intermittent heat generation that repeats on for 10 seconds and off for 10 seconds. And when the first predetermined time T1 has elapsed from the start of rice cooking,
Stop heat generation (steps S14, S15). Further, when the second predetermined time T2 has elapsed after that, the pot temperature sensor
The detected temperature P1 of 23 is read again (steps S16, S17
), As shown by the broken line graph in FIG. 5, if the detected temperature increase P1−P0 is α1 or more, it is determined that the temperature detection by the temperature sensor 23 is normal, and heating of the cooked rice is continued (step S18, S19). On the other hand, as shown by the solid line graph in FIG. 1, if the detected temperature increase P1-P0 is less than α1, it is considered that the temperature detection by the pan temperature sensor 23 is abnormal (step S20), and the rice cooking is stopped. (Step S2
1) After that, the pan 4 does not generate heat.

In the second embodiment, the same operational effect as that of the first embodiment can be obtained. In addition to that, according to the configuration of the second embodiment, after the rice cooker 4 starts to generate heat for the first predetermined time T1 from the start of rice cooking, the heat generation for the second predetermined time T2 is stopped and the second predetermined time T2 When the rise in the temperature detected by the temperature sensor 23 after the end is less than or equal to the predetermined temperature rise value α1, rice cooking is stopped, so that the temperature detection of the pot temperature sensor 23 is not affected by heat due to electromagnetic induction and the pot 4. Therefore, the situation of the temperature detection accuracy of the pot temperature sensor 23 can be determined by whether or not the rise in the temperature detected by the pot temperature sensor 23 is a temperature rise value that should be obtained at normal times due to the heat generation for the predetermined time T1. There is less erroneous detection, and there is an advantage that an abnormal temperature detection of the pan temperature sensor 23 can be detected.

The graph of FIG. 7 and the flowchart of FIG. 8 show the third embodiment of the present invention. In the third embodiment, the microcomputer 61 has, as a function on its software, a continuous heat generation in the pan 4 from the start of rice cooking, and after a lapse of a predetermined time T3 after the temperature detected by the temperature sensor 23 reaches a predetermined temperature β. When the rise in the temperature detected by the temperature sensor 23 is less than a predetermined temperature rise value α2, the heat generation by the induction heating means 72 and the heat generation by the heaters 21, 51 are stopped. Then, in this embodiment, the predetermined temperature β is set to 50 ° C., the predetermined time T3 is set to 300 seconds, and the predetermined temperature increase value α2 is set to 15 ° C. Of course, it is also possible to set other than these values. However, the predetermined time T3 for causing the pan 4 to generate a predetermined amount of heat is set so that abnormal heating such as melting of plastic parts does not occur, and the predetermined temperature rise value α2 is the temperature measured by the pan temperature sensor 23. It is set to be less than the rise value of the temperature detected by the pan temperature sensor 23 that occurs when the detection is normal. Furthermore, the relationship between the predetermined time T3 and the operation of the temperature fuse 22, the relationship between the predetermined temperature rise value α2 and the power supply voltage, and the predetermined temperature rise value α2 and the separation between the pan temperature sensor 23 and the pan 4. The relationship is set as in the first embodiment.

Then, rice cooking is started (step S31).
At the same time, heat generation in the pan 4 starts (step S32). This form of heat generation is continuous heat generation. And the pot temperature sensor 23
When the temperature detected by the pan reaches the predetermined temperature β, the temperature detected by the pan temperature sensor 23 becomes β when the predetermined time T3 elapses from that time.
It is determined whether it is less than + α2 (step S33).
, S34, S35). Here, as shown by the broken line graph in FIG. 7, if the temperature detected by the pan temperature sensor 23 is β + α2 or more, that is, if the temperature rise in the pan 4 during the predetermined time T3 is α2 or more. If there is, it is determined that the temperature detection by the temperature sensor 23 is normal, and the rice cooking heating is continued as it is (step S36). On the other hand, as shown by the solid line graph in FIG. 7, the temperature detected by the pan temperature sensor 23 is β + α.
If it is less than 2, that is, if the detected temperature rise during the predetermined time T3 is less than α2, it is determined that the temperature detection by the pan temperature sensor 23 is abnormal (step S37), and the pan 4
Heating of rice is stopped, and heating of cooked rice is stopped (step S38).
).

In the third embodiment, instead of using the time when the temperature detected by the pan temperature sensor 23 reaches the predetermined temperature β as the starting point of heat generation of a predetermined amount of heat, the heat generation time from the start of rice cooking is a predetermined time, for example, Pan temperature sensor at 180 seconds
The detected temperature of 23 may be stored, and the deterioration of the detection accuracy of the pan temperature sensor 23 may be detected from the temperature rise after the T3 heat generation continues for a predetermined time from that point.

As in the third embodiment, the abnormality in the temperature detection of the pan temperature sensor 23 may be performed during the cooking of rice. With this, the same effect as that of the first embodiment can be obtained.

The present invention is not limited to the above embodiment, and various modifications can be made. For example,
The heat generation of the pan 4 for detecting the presence or absence of temperature detection abnormality from the rise of the detected temperature may be continuous heat generation as in the first and third embodiments or intermittent heat generation as in the second embodiment. However, the output may be changed with time, and the point is that the pan 4 is caused to generate a predetermined amount of heat. Further, although the rice cooker has been described as an example in the above embodiment, the present invention can be applied to cookers other than the rice cooker.

[0042]

According to the first aspect of the present invention, the container generates heat by the heat generating means, and the heat generation amount of the heat generating means is adjusted so that the temperature detected by the temperature detecting means becomes the cooking temperature set within the predetermined temperature range. In the controlled cooker, when the detected temperature when the heat generating means generates a predetermined amount of heat is within the predetermined temperature range and the increase in the detected temperature is less than the predetermined temperature increase value, the heat generation of the heat generating means is stopped. When, for some reason, the detection accuracy of the container temperature deteriorates, this can be detected, the situation in which abnormal heating occurs can be prevented, and safety is improved.

Further, according to the cooker of the second aspect of the present invention, the cooker is provided with a temperature fuse connected to the heat generating means in a series circuit, and the predetermined amount of heat does not operate when the container is empty. Since the temperature is set within the range, when the detection accuracy of the container temperature deteriorates, it is possible to stop the heat generation before the operation of the temperature fuse.

According to the cooker of the invention of claim 3,
Since the predetermined temperature rise value is set to be equal to or lower than the temperature rise that occurs when the power supply voltage supplied to the heat generating means is 80 V or more in a normal state, even if there is some error in the power supply voltage, the temperature of the container can be detected. Can accurately detect abnormalities.

According to the cooker of the invention of claim 4,
Since the predetermined temperature rise value is set to be equal to or higher than the detected temperature rise that occurs when the temperature detecting means is completely separated from the container, it is possible to prevent the cooking from being stopped unnecessarily due to an erroneous detection of an abnormality.

According to the fifth aspect of the present invention, the container heat is generated by the heat generating means, and the heat generation amount of the heat generating means is controlled so that the temperature detected by the temperature detecting means becomes the cooking temperature set within the predetermined temperature range. In the cooking device to be cooked, the heating means is caused to generate a predetermined amount of heat after starting the cooking, and then the heating is stopped for a predetermined time, and the cooking is performed when the rise in the detected temperature after the end of the heat generation is less than the predetermined temperature rise value. Since the operation is stopped, when the detection accuracy of the container temperature deteriorates for some reason, this can be detected more accurately, a situation in which abnormal heating occurs can be prevented, and safety is improved.

[Brief description of drawings]

FIG. 1 is a graph showing a detected temperature and a timing of heat generation, showing a first embodiment of the cooker according to the present invention.

FIG. 2 is a flowchart of the above.

FIG. 3 is a block diagram showing an electrical configuration of the same.

FIG. 4 is a sectional view of the same rice cooker as above.

FIG. 5 shows a second embodiment of the cooking device of the present invention and is a graph showing the detected temperature and the timing of heat generation.

FIG. 6 is a flowchart of the above.

FIG. 7 is a graph showing the detected temperature and the timing of heat generation, showing the third embodiment of the cooking device of the present invention.

FIG. 8 is a flowchart of the same as above.

[Explanation of symbols]

4 Pan (container) 22 Thermal fuse 23 Pan temperature sensor (temperature detection means) 61 Microcomputer (cooking control means, heat generation stop means, cooking stop means) 72 Induction heating means (heat generation means)

Claims (5)

[Claims] 1. A container for containing cooked food, a heat generating means for generating heat from the container, a temperature detecting means for detecting the temperature of the container, and a temperature detected by the temperature detecting means are set within a predetermined temperature range. Cooking control means for controlling the amount of heat generated by the heat generating means so as to reach the cooking temperature, and the temperature detected by the temperature detecting means when the heat generating means generates a predetermined amount of heat within the predetermined temperature range and the detected temperature. And a heat generation stopping means for stopping heat generation of the heat generating means when the temperature rise is less than a predetermined temperature increase value. 2. A temperature fuse connected to the heat generating means in a series circuit, wherein the predetermined amount of heat is set within a range in which the temperature fuse does not operate when the container is empty. The cooker according to 1. 3. The cooker according to claim 1, wherein the predetermined temperature rise value is set to be equal to or lower than a temperature rise that occurs when the power supply voltage supplied to the heat generating means is 80 V or more and is normal. 4. The cooker according to claim 1, wherein the predetermined temperature rise value is set to be equal to or higher than a detected temperature rise that occurs when the temperature detecting means is completely separated from the container. 5. A container for containing cooked food, a heat generating means for generating heat from the container, a temperature detecting means for detecting the temperature of the container, and a temperature detected by the temperature detecting means are set within a predetermined temperature range. The cooking control means for controlling the heat generation amount of the heat generation means so as to reach the cooking temperature, and after the cooking control means starts cooking, the heat generation means is caused to generate a predetermined amount of heat, and thereafter, when the heat generation is stopped for a predetermined time, the heat generation is stopped. A cooking device comprising: cooking stopping means for stopping cooking when the temperature detected by the temperature detecting means after the stop time has risen is less than a predetermined temperature increase value.